The leisure diving industry has experienced substantial growth. The apparatus used in that industry are specifically designed so that divers do not need to undergo certification before being able to dive.
In particular, such apparatus usually include a one-piece moulding that rests on a diver's shoulders. The principle behind these apparatus is that they trap air in a breathing zone about a diver's head. Air is then pumped into this zone from the surface to permit a diver to breathe. This is an ancient concept and has been used for many years to supply breathable air to a diver.
The breathing zone defined by these apparatus is relatively large and therefore generates a substantial buoyant force. It follows that the apparatus must be of sufficient weight to ensure that the apparatus remains on a diver's shoulders. This has resulted in presently used apparatus weighing as much as 35 Kg. This weight is exerted on the diver's shoulders. It will be appreciated that a combination of the diver and such an apparatus has a high centre of gravity.
These characteristics have led to a number of disadvantages.
The primary disadvantage is that of safety. The high centre of gravity results in a situation where a diver can easily tip over if he or she loses their balance. This can result in the air in the breathing zone being replaced by water, adding even more weight to the apparatus. This extra weight can quickly drag a diver over, resulting in drowning and injury. This tipping over can also occur if the hooker line becomes snagged on an underwater object. It follows that a diver must always be sure to remain erect. This is inconvenient and limits the maneuverability of the diver.
A further problem associated with the weight of the apparatus is that it is not possible for a diver to get to the surface in case of an emergency. This is one of the reasons why such apparatus have not achieved accreditation with the various dive organizations.
The weight of the apparatus often makes it difficult for less robust divers to walk about safely. It follows that they often require a stationary bar to grasp in order to stabilize themselves.
As a result of the weight of the apparatus, it is extremely difficult to manipulate them out of water. In order to place one of them on the shoulders of a diver, it is often necessary to lower the apparatus on to the shoulders using a block and pulley system with a rope or cable attached to the apparatus. If an instructor's hands are wet, the rope or cable could slip, resulting in injury to the diver.
Another disadvantage is that associated with the volume of the breathing zone. The volume is such that it is not feasible to provide the apparatus with an independent back up air supply, such an air supply would require a tank that would be too big to form part of the apparatus. Thus, the apparatus is not supplied with a back up system. This is another reason why the apparatus have not achieved accreditation with the various dive organizations.
The apparatus do not include a regulator and a constant flow of air is supplied to the breathing volume. It follows that exhaust air mixes with fresh air and both often escape. As is known in the industry, it is relatively expensive to pump air to such an apparatus. It follows that such wastage is undesirable. This is exacerbated by the fact that the apparatus requires a high volume output compressor in order to accommodate different depths.
Commercial-type diving rigs are not considered for the leisure and recreational market. The primary reason for this is comfort and the fact that such rigs are not photo-friendly. These rigs fasten rather tightly about a diver's neck. This can lead to substantial discomfort. These rigs include a face piece which engages a diver's mouth and nose. This renders the diver unrecognisable and so reduces the opportunity for photography.
A problem associated with masks that trap a breathing space about a diver's face is that it becomes difficult to equalize, which is a procedure achieved by pinching the nostrils closed and “popping” the eardrums. Clearly, with the rational apparatus described above, this is not a disadvantage, since the diver can simply manoeuvre his or her hand into the helmet to pinch the nostrils closed. With presently available commercial rigs, the diver must allow water to enter the mask with his or her hand and then expel the water. It will be appreciated that this could be too traumatic or difficult for recreational divers who would generally use the recreation apparatus described above.
Applicant has identified the need for a diving apparatus that can address the disadvantages associated with the presently used recreational rig, while providing an easy means for equalization.